What more do we gain by having permissive on instead of SELinux
completely off?

file contexts are set correctly to some extent (aren't they?), so
switching to enforcing mode would be a shorter, not longer path.

However permissive has most of the performance overhead, but none of the
security benefit of enforcing, right? I personally think the user
should choose between off or on, and endure the lengthy process if they
want to transition from off to on.